Terms used for Depreciation:

1. Amortization: This refers to loss in the value of intangible assets such as goodwill, patents and preliminary expenses.

2. Depletion: Decrease in the value of mineral wealth such as coal, oil, iron ore, etc. is termed as depletion. The more we extract mineral wealth, the more they are depleted.

3. Obsolescence: When an asset becomes useless due to new inventions, improved techniques and technological advances, it is termed as obsolescence.